Mathematisch-Naturwissenschaftliche Fakultät

Institut für Physik

Fachgebiet: Theoretische Physik

Betreuer: Prof. Dr. Heinrich Stolz

Dipl.-Phys. Patrick Ludwig
(e-mail: )

Structure Formation in Strongly Correlated Few-Particle Systems in Traps

The objective of the present work is the theoretical investigation physical structure formation by means of computational simulation methods. Of particular interest are charged few-particle systems in external trapping potentials, which allow one to realize and control strong correlation and quantum effects. Such 'artificial atoms' have unique features absent in real atoms: by controlling the confinement strength they can be transformed from a weakly coupled state to a strongly coupled, crystal-like phase.

The first central topic is devoted to the structural properties of 3D Coulomb crystals, which have been observed in trapped ion systems as well as in (multi-component) complex plasmas. The ground state properties, such as the shell structure, are studied by first-principle molecular dynamics simulations. The detailed comparison of the theoretical results with experiments provides the basis for a theory of these strongly correlated classical systems.

The second major topic concerns electron-hole quantum plasmas in dimensionality reduced semiconductor heterostructures. At first, the realization of a quantum Stark confinement for spatially indirect excitons in a single quantum well is investigated in view of an experimental implementation. Furthermore, the effects of field-strength, temperature, density, exciton dipole moment, and electron-hole mass asymmetry are extensively studied by means of quantum Monte Carlo simulations. As a universal melting criterion for classical and quantum few-particle systems a modified version of the Lindemann parameter for the pair distance fluctuations is introduced.